Cartridge-shell.



P. BUTLER. CARTRIDGE SHELL. APPLICATION FILED JULY 29, 1912.

1,1 18,888. Patented Nov. 24, 1914.-

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PAUL BUTLER, or LOWELL, MASSACHUSETTS.

CARTRID (-IrE-SI-IELL.-

Specification of Letters Patent.

Patented Nov. 24., 1914.

Application filed July 29, 1912. Serial No. 711,969.

To all whom it may concern:

Be it known that I, PAUL BUTLER, a citizen of the United States, residing in'Lowell, in the county of Middlesex and State of Massachusetts, have invented an Improvement in Cartridge-Shells, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

The present invention relates to a cartridge shell, and is embodied in a cartridge shell of the kind which is known as a paper shell in which a paper tube is inserted in a drawn metal cup and held therein by means of a Wad which is forced into the cup after the tube has been inserted. In shells of this kind there is a tendency for the paper tube to break at the point where it emerges from the cup, and it is desirable that the construction should be such as to admit of a slight longitudinal yielding movement of the paper tube with relation to the cupat the time of the explosion. It is also desirable that the paper tube should be firmly held in the cup so as to resist the actual separation of the parts.

In accordance with the present invention, the metal cup is provided with a plurality of inclined grooves around the periphery of the cup, and adjacent to the wad which, when compressed, forces the paper tube into the inclined grooves or corrugations of the cup, so that said tube conforms to the shape of the cup when the shell has been assembled. This grooving or corrugation of the metal cup admits of a slight expansion thereof under the pressure of the expanding gases, thus allowing the paper tube and the cup to be slightly elongated owing to the tendency thereof to be expanded by the pressure and forced more nearly to a true cylindrical shape. Furthermore, by inclining the grooves or corrugations with relationto the base of the cup, the paper tube has a tendency to be slightly turned when the gas pressure is exerted, thereby facilitating the relative longitudinal movement of the tube and cup which is required to prevent the tube from bursting along the edge of the cup.

Figure 1 is a side elevation of a shell embodying the invention; and Fig. 2 is a vertical section of the shell shown in Fig. 1.

In the drawings, the dimensions are largely exaggerated for the purposes of illustration, the practice being to make the metal cup as thin as possible and especially tothin the edges of the same where it ad- Joins v the paper tube, so that the side of the paper tube and the side of the cup will he as close as possible to the wall of the chamberof the gun, leaving the least possible amount of room for the tube to expand and be out by the edges of the cup. In spite of these precautions, however, it is found that if the paper tube is held absolutely rigid 1n the cup, it is likely to burst at this point, and it is desirable, therefore, to provide means whereby the tube can move longitudmally to a slight degree with relation to the end of the cup, thereby lessening the strain at this point.

In accordance with the invention, the metallic cup at is provided with a series of corrugations a which are inclined with rela tion to the plane of the base of the cup, as clearly shown in Fig. 1. These corrugations are alike outside and inside the cup, since they are formed by bending the wall of said cup, and the paper tube Z1, when inserted in the cup is forced outward by the lateral pressure of the wad due to the longitudinal compression thereof, so that the said tube conforms to the corrugations, it being obvious, therefore, that both the tube and the cup are capable of some elongation when the-cup and tube are expanded by the explosion of the cartridge. The tube, however, is firmly held in the cup and resists actual separation therefrom to a greater extent than is the case in shells in which the frictional contact between the wad and the cup is mainly. relied upon to hold the parts together.

What I claim is:

As an improved article of manufacture, a

cartridge shell comprising a paper tube, an

interior wad, and an exterior metal cup arhaving a plurality of parallel inclined name to this specification in the presenceof grooves extending in the direction of the two subscribi ng Witnesses. length of the shell and :ifiording an inti- PAUL B v mate and strong union "of the tube and cup i 5 sufiicient to resist the tendency of the tube Witnesses: 1

and cup to separate in use. JAS. B. RUSSELL,

In testimony Wl16I60f,'I havesigned my ALBERT W. DAVID.

Copies of this patent may be obtained for five cents each, by addressing the r Washingtony D. G.

Commissione: of Patents, 

